Piles are often used in construction to support structures, roadways, earthworks, and the like. At least a portion of a pile is typically arranged within the ground. While a pile may be placed into an excavated hole, piles are typically driven into the ground by the application of a driving force to the top of the pile. The driving force may be one or more of static forces (e.g., weight of pile and pile driving equipment), impulse forces (e.g., drop hammer, diesel hammer), crowding forces (e.g., hydraulic ram), and vibratory forces (e.g., eccentric vibro). The exact nature of the driving force is typically selected for a particular type of pile and, to some extent, to a particular set of soil conditions.
A pile is typically driven by applying the driving force along a longitudinal axis of the pile being driven. As discussed above, a driving force applied to a pile to be driven often includes a vibratory force component. The vibratory force component results in forces being applied to the pile being driven in both directions along the longitudinal axis of the pile. Depending on the nature of the pile and soil composition, vibratory forces can significantly enhance the speed at which piles are driven. Vibratory forces can also be gentler on a pile structure being driven than, say, impulse forces.
Vibratory forces are highly appropriate for use with certain concrete piles and certain soil conditions. The present invention is of particular relevance in the context of applying a driving force having a vibratory force component to a concrete sheet pile. In general, a sheet pile may be characterized as having a width dimension that is significantly greater than a thickness dimension. Therefore, in comparison to a pile driver for cylindrical piles, at least a portion of a pile driving system for sheet piles is typically adapted to accommodate the wide and thin form factor of sheet piles. The form factor of a concrete sheet pile is also basically wide and thin, but a concrete sheet pile is typically a precast, reinforced, concrete structure.
In the context of concrete sheet piles being driven with a driving force having a vibratory force component, the pile driving system typically comprises a vibratory device and a clamp system. The vibratory device generates the vibratory force component, and the clamp system ensures that the vibratory forces are applied in both directions along the longitudinal axis of the pile being driven. The clamp system is adapted for the particular form factor of the pile being driven.
The need exists for improved pile driving systems and methods for concrete sheet piles and, more specifically, to clamp systems and methods for effectively applying the vibratory force component of a driving force to a concrete sheet pile with minimal damage to the concrete sheet pile.